1. Field of the Invention
The present invention relates generally to footwear, and more particularly to shoe uppers having smooth interior and/or exterior upper surfaces and related methods to produce such shoe uppers.
2. Background Art
Shoe uppers generally have been formed by stitching together a plurality of exterior panel sections. These exterior panel sections can be made of leather, synthetic leather, plastic, mesh, textile, or other materials. Conventional stitching is time consuming, labor-intensive, and costly wherein the end result is an aesthetically-unpleasing seam line. The conventionally stitched seam also suffers from the drawbacks of adding excess weight to the shoe and having a thick profile which can be uncomfortable for the wearer. It is often desirable to use open-faced materials for the exterior panel sections, for example mesh materials, to enhance the breathability of the shoes. These materials are particularly appropriate for athletic shoes. Such materials are challenging to join together using conventional stitching techniques. A designer of shoe uppers may wish to produce an upper with a highly curved three-dimensional surface formed from an assembly of three-dimensional panel sections. Such a surface may require seams that would prohibit the use of conventional stitching machines, which are generally limited to two-dimensional (flat) bonding applications.
The interior linings of shoes have generally also comprised several panels or sections which are stitched together at various interior seams. Since the lining directly abuts the wearer's foot, these seams can become sources of irritation or discomfort to the wearer.
In an effort to avoid or reduce the disadvantages inherent with using conventional stitching to join exterior panel sections of a shoe upper, designers have experimented with a variety of unitary shoe upper designs. These designs suffer from several disadvantages that paneled uppers do not. For example, it is difficult to construct a unitary upper that displays different characteristics (such as rigidity, thickness, or cushioning) in different areas of the upper. Either the designer will have to settle for an upper that has uniform characteristics, or additional costly and time-consuming manufacturing steps will have to be incorporated. Another drawback to unitary uppers is that they are often not as aesthetically pleasing to the consumer as an upper formed by a plurality of exterior panel sections.
Accordingly, there is a need to have an improved shoe upper which combines the advantages of both the paneled (sectional) and unitary shoe upper designs without inheriting the limitations or disadvantages of either. It is desirable to have a sectional shoe upper that has strong, aesthetically-pleasing seams of low profile which can be produced in a cost-effective and timely manner. The improved upper should allow the designer to be free to select from a wide variety of upper materials and upper shapes, including three-dimensional shapes. There is also a need to minimize or reduce the discomfort generated from interior lining seams.